Composite signaling system



Feb/5 1924.

B. P. HAMILTON COMPOSITE S IGNALING ,SYS TEM Filed Sept. 23. 1919 IN VEN TOR.

- ATTORNEY Patented Feb. 5, i924.

UNE? iaa BAX'IER 1?. HAMILTON, OE BROOKLYN, NEW YORK, ASSTGNOR TOAMERICAN TELE- PHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

COMPOSITE SIGNALING SYSTEM.

Application filed September 2-3, 1919.

1 all whom it may concern:

Be it known that I, BAXTER P. HAMILTON, residing at Brooklyn, in thecounty of Kings and State of New York, have invented certainImprovements in Composite Signaling Systems, of which the following is aspecification.

This invention relates to composite signaling circuits and moreparticularly to circuits in which carrier signals are superposed upontelephone lines composited for Morse operation.

One of the features of this invention resides in an arrangement wherebya carrier channel may be superposed upon each Morse leg of a compositedtelephone line.

Another feature of the invention resides in an arragement whereby atelephone line composited for Morse operation may have two signalingchannels of the same carrier frequency adapted for signaling in eitherdirection, superposed thereon.

The above features, as well as other char acteristics of the inventionmore fully hereinafter appearing, are realized in thearrangementdisclosed in the accompanying drawing, the figure of whichillustrates one embodiment of the invention.

Referring to the drawing, ML designates a telephone transmission line ofthe usual type, terminating in jacks J and J, at stations A and Brespectively, whereby the line may be associated with terminal telephoneapparatus. The line may be phantomed in the usual manner, by providingphantom coils PC and PC, as indicated. In order to utilize the twoconductors of the line ML for. the transmission of Morse signals,composite apparatus GK and CK of the usual type is provided at eachterminal of the line. As this composite apparatus is old in the art andis well understood, it need not be described in detail. Morse signalsmay be transmitted from the Morse leg 1 over the upper side of the lineML to the Morse leg 1, or vice versa. In a similar manner Morse signalsmay be at the same time transmitted in either direc tion over thecircuit including the Morse leg 2, the lower conductor of the line MLand the Morse leg 2. In order that an alternating carrier currentchannel may be superposed on the Morse connections, a transmittingcircuit TC is associated through a transformer 4 with Morse leg 2,similar Serial No. 325,682.

transmitting circuits (not shown) being associated with Morse legs 1, 1and 2, through transformers 3, 3 and 4'. For receiving the carriersignals tuned branches TB and TB are connected to the Morse legs 2 and2, as shown, it being understood that similar receiving branches will beassociated with Morse legs 1 and 1. The transmitting circuit TC includestransmitting apparatus schematically indicated as an alternating currentgenerator G and a transmitting key K. A receiving circuit is, of course,associated with each tuned branch, such as TB, the receiving circuit RCassociated with this particular branch being illustrated as including analternating current receiving relay RR.

By actuating the key K alternating currents from the generator G may beimpressed from the transmitting circuit TC through the transformer 4upon the Morse leg 2 and transmitted over the lower conductor of themain line ML to the Morse leg 2. The tuned branch TB selects the carrierfrequency thus transmitted and impresses it through transformer 5 uponthe receiving circuit R0 to actuate the receiving relay RE. The carriertransmission at the same frequency may also take place either in thesame or in the opposite direction over a path, including Morse leg 1,upper conductor of ML and Morse leg 1.

It will be obvious that the general principles herein disclosed may beembodied in many other organizations widely different from thoseillustrated, without departing from the spirit of the invention asdefined in the following claims:

What is claimed is:

1. In a signaling system, a telephone transmission line, compositeapparatus in cluding Morse legs for transmitting Morse signals over oneside of said telephone line, similar apparatus including Morse legs fortransmitting Morse signals over the other side of said line, and carrierapparatus associated with said Morse legs for transmitting alternatingcarrier currents modulated by signals through said Morse legs and oversaid line.

2. In a signaling system, a telephone transmission line, compositeapparatus associated therewith including Morse legs for transmittingMorse signals over one side of said telephone circuit, similar apparatusIOU 2 means? including Morselegs for transmitting Morse said Morse legswhereby alternating carriercurrents modulated by signals may betransmitted through each of said Morselegs and over each side of thetelephone line.

3. In a signaling system, a telephone transmission line compositeapparatus, including Morse legs associated therewith for superposingMorse signals upon onesideof said telephone line, similar apparatus in.-

cluding Morse legs. for transmitting Morse, signals, orer the, other sde ofsaid line, tuned branches associated with said Morse legs, andcarrier a paratus associated wlth sald tuned branches.

a. In, a signaling systerm. telephone transmission line, compositeapparatus including Morse legs associated with said line fortransmitting Morse signals over one side of said telephone line, similarapparatusim eluding Morse legs for transmitting Morse signals over theother side of said line, tuned branches connected with said vMorse legs,carrier transmitting apparatus associated With each of said Morse legs,and carrier receiving apparatusassoeiated with each of said.tunedhranches.

In testimony whereof, I have. signed my name to thisspeeification this20th day of September, 19-19.

BAXTER P. HAMILTON.

